Adjustable pedal assemblies are well known for use in a vehicle to provide a driver of the vehicle with a manner of adjusting a distance between the driver and pedal levers used to control the vehicle. A typical adjustable pedal assembly comprises a support for mounting the adjustable pedal assembly to the vehicle. A first pedal lever, such as an accelerator pedal lever, is supported for rotation about an operational axis relative to the support. A first adjustment mechanism adjusts the first pedal lever between a first plurality of adjusted positions relative to the support. A second pedal lever, such as a brake pedal lever, is supported for rotation about a second operational axis relative to the support. A second adjustment mechanism adjusts the second pedal lever between a second plurality of adjusted positions relative to the support. As will be appreciated by those skilled in the art, each of the first and second adjustment mechanisms typically comprise a transmission connected to a drive screw to rotate the drive screw and drive a nut axially within a guide rod. The nuts are coupled to the pedal levers to adjust the pedal levers as the nuts translate along the drive screws. A single motor is connected in series to the transmissions by a pair of rotary cables. The motor drives the transmissions to rotate the drive screws to adjust both pedal levers between the adjusted positions. Such a system is shown in U.S. Pat. No. 5,722,302 to Rixon et al. and U.S. Pat. No. 5,964,125 to Rixon et al.
As adjustable pedal assemblies have developed over the last several years, specifications concerning their use have also developed. One such specification is that of minimizing pedal lever “step-over.” Step-over occurs when the first and second pedal levers become misaligned during adjustment. When the pedal levers are misaligned, the driver may have difficulty quickly adjusting to the relative positions of the first and second levers. As a result, there has come a need in the art to minimize pedal lever step-over.
A system and method for controlling pedal lever step-over in adjustable pedal assemblies are suggested in U.S. Pat. Nos. 6,352,007 and 6,510,761 to Zhang et al. In each of these patents, sensors are utilized to detect when step-over occurs between two or more pedal levers during adjustment. Specifically, hall-effect sensors are positioned adjacent to drive screws used to adjust the pedal levers to directly sense rotation of the drive screws and detect step-over. When the sensors indicate that step-over has occurred, power to a motor, which rotates the drive screws, is discontinued and adjustment of the pedal levers ceases. The hall-effect sensors disclosed in Zhang et al. do not directly sense translation of the pedal levers. Instead, the hall-effect sensors directly sense rotation of the drive screws and convert the rotational information into relative positions of the pedal levers.
A system for controlling pedal lever step-over is also shown in U.S. Pat. No. 6,450,061 to Chapman et al. The '061 patent discloses a system that integrates adjustment of two or more pedal levers into a circuit for powering a motor used to adjust the pedal levers. In this system, if the pedal levers fall out of alignment, the circuit is broken and power to the motor is discontinued. An intricate motor control switch actuated by pull cables connected to each of the pedal levers integrates adjustment of the pedal levers into the circuit. When the pedal levers do not adjust simultaneously, the pull cables actuate the switch and the switch moves to an open state. When the switch is open, the circuit is open and power to the motor is discontinued. A separate potentiometer is needed in Chapman et al. to track a position of the pedal levers for memory purposes. The potentiometer is coupled to the pull cables to sense the position of each of the pedal levers.
While prior art systems and methods have been developed for controlling step-over between pedal levers, these systems are often complicated and/or costly. There still remains a need in the art of step-over control for a simplified system that utilizes well-known, inexpensive, multi-functioning components. At the same time, there is a need for step-over control that relies on directly sensing translation of the pedal levers to minimize errors in the detection of step-over.